Traveling abroad is an exciting yet stressful endeavor that can result in long days in unfamiliar places, which can make the chance of saying something rude, whether unknowingly or knowingly, a reality.

While most people don’t go on a trip with the intention of offending people in the country they’re visiting, it does happen, and experts told HuffPost they’ve seen it firsthand time and time again.

Below, a travel professional and etiquette expert share the rudest things people say when traveling abroad.

“Something I actually heard: I was in London last week, somebody was arguing with the front desk of the hotel, and they were saying, ‘Well, the customer is always right,’ and it’s sort of like, that’s actually a very American approach to customer service,” said Nick Leighton, an etiquette expert and host of the “Were You Raised by Wolves?” podcast.

It’s not a globally-shared thought pattern. “And very often, the customer is not right,” Leighton added.

“In a lot of places around the world, a business is happy to push back on that,” he said. Meaning, you may not get the outcome you’re hoping for.

“You sometimes hear stories [where] somebody’s in a restaurant in Italy and they ask for Parmesan cheese to put on their fish, and the restaurant’s like, ‘No, we’re not gonna let you do that,’” he said. This often results in an upset customer who utters a phrase like “the customer is always right” or “I’m the customer” only to be met with further refusal from the restaurant.

So, before you assume you can do no wrong as a patron of a business, remember that this is an extremely American idea.

According to Chelsea Glass, the founder and CEO of Heart of Travel, an ethical travel tour company, the use of the term “Third World country” is another no-no, especially when it’s just as easy to say “developing nation” or simply refer to the country by its name.

“Third-world country has negative connotations and is also just an inaccurate term,” Glass said.

This should go without saying, but just because you’re visiting a country that uses a different currency doesn’t mean their money is any less “real” than the U.S. dollar.

“The U.S. dollar is a very popular currency around the world, but Mexico pesos are also real money. Euros are also real money,” Leighton said, “and I think people are not saying the phrase ‘real money’ in some sort of way that’s commenting on the dollar standard, but it does come across as like, ‘Oh, our money is real and everything else is not real.’”

It’s also not a good idea to comment on how “cheap” something is when visiting a country with a weaker currency.

Or, oppositely, to complain about how “expensive” something is in a place where you didn’t expect to pay top dollar.

“I think people have this gross overestimation that the U.S. dollar is so powerful in these countries and it goes so far,” Glass said. “When, in reality, if you look at the cost of living, look at the labor involved, people are still underpaid in these places.”

People often have a false idea of just how powerful the U.S. dollar is when that isn’t really true in the global economy, Glass noted.

Calling people “exotic” is condescending, said Leighton, even if you mean it in a nice way.

“Anything down that road, this is not great,” he added. Similarly, “Anything where we’re starting to romanticize, especially poverty — ‘Oh, this place is so authentic.’ This is also not great,” he said.

“I think anywhere you might be traveling, even poorer areas in the United States, if you find it charming and authentic that people have different living conditions, I think that can come across in a way that maybe you don’t intend,” Leighton noted.

“I think one obvious one is when people angrily demand that people in the country they’re visiting speak English when English is not the native language of that country,” Glass said.

She added that she’s seen this on multiple occasions. “I’ve seen travelers be rude to waitresses inside cafés in Mexico City because they’re not speaking English,” Glass added.

Instead, you should take time to learn a few key words in their language.

“Making a little effort with the local language, even if it’s just as simple as learning ‘hello,’ ‘please’ and ‘thank you,’ that shows a lot to the people in that country that you’re trying,” Glass said.

Traveling abroad can bring you face-to-face with customs that are unfamiliar, whether you’ve never seen them before or the habits haven’t been part of American life for some time. Either way, “It’s not your place to comment on someone’s culture … that’s their tradition,” said Leighton.

So if you’re surprised to see certain behaviors or habits, you shouldn’t utter a phrase like, “Oh, I can’t believe they still do that here,” whether referring to the use of plastic straws or a specific cultural tradition, he added.

“I think the broader theme is just assuming the way that you do something is the way that it should be done, or is the only way to do something, or is the best way. I think this often gets us into trouble,” said Leighton.

“And I think the more you travel, the more you realize, ‘Oh, the way we do it back home is actually not the way,’” he said.

Recently, Glass said she’s noticed an increase in folks questioning the safety of Latin America and referring to those who are being deported to countries like Guatemala from the U.S. as “criminals.”

Talking about “criminals” as you visit a new Latin American country is misinformed and rude.

“First of all, not all the people who are getting deported back to Guatemala are criminals. Most of them, their only, if you want to even call it crime, is that they are existing in the United States without paperwork,” said Glass.

“These are not murderers or rapists, and really, oftentimes, have zero criminal record,” she noted.

“And also … do you think that they’re just going to deport hundreds of criminals and then let them loose onto the streets in Guatemala? That’s not how it works. The ignorance and the lack of understanding of how the whole process works,” she said.

If you go into an international trip with the attitude that you’re a guest in another country, you’ll be more likely to act in a way that honors the locals and respects the traditions, said Leighton.

“As a guest, I want to do all the guest things. We would never go to a friend’s house as a guest, and then start criticizing everything,” Leighton noted. “So, why do we do that when we’re traveling abroad?”

The high cost of vacations and the few PTO days most companies give people combine to make people feel like they’re entitled to a certain experience, he added.

“But, I think because of that, we feel entitled to act however we want and feel like, ‘Oh, there aren’t consequences,’ but etiquette still applies,” Leighton said.